GB1588989A

GB1588989A - Means for collecting and removing oil from water

Info

Publication number: GB1588989A
Application number: GB41835/77A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-10-08
Filing date: 1977-10-07
Publication date: 1981-05-07
Also published as: US4059962A; NO149855C; NO773428L; NO149855B; CA1114750A

Description

PATENT SPECIFICATION

( 11) 1 588 989 ( 21) Application No 41835/77 ( 22) Filed 7 Oct 1977 ( 31) Convention Application No.

730811 ( 32) Filed 8 Oct 1976 in ( 33) United States of America (US) ( 44) Complete Specification published 7 May 1981 ( 51) INT CL 3 E 02 B 15/04 ( 52) Index at acceptance 1 Bl D 1501 1705 1708 1711 1714 CA ( 54) IMPROVEMENTS IN AND RELATING TO MEANS FOR COLLECTING AND REMOVING OIL FROM WATER ( 71) I, JEROME H MILGRAM, of 23 Mellen Street, Cambridge, Massachusetts 02138, United States of America, a Citizen of the United States of America, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be described in and by the following statement:

This invention relates to a skimming subassembly for removing oil on water and which is adapted to be mounted, in use, upon an elongated flexible barrier sheet.

More generally the invention relates not only to the confining of oil but also for collecting of oil to be pumped from a body of water.

There has long been a need for apparatus for accomplishing the dual purposes of confining oil spilled on bodies of water and collecting it to be pumped to separation and storage locations, usually aboard boats or ships The problems of providing such dual purpose apparatus which is also suitable for use in the environment of rough seas is even more challenging Furthermore, the apparatus must be readily transportable, often by air, relatively light in weight, compact and adapted to withstanding very substantial forces attending its deployment and usage The result of the very stringent requirements is that heretofore, the confinement and collection have largely been accomplished by separate devices, a floating barrier for sweeping polluted waters to concentrate the oil in a thickened layer inside the central portion of the barrier and for confining the oil, and a separate oil intake floating in the confined pool and connected to pumps for removing the oil from the confined area There have also been crude attempts to combine both functions by using slotted hoses floating on the surface of the water and connected to pumps but such expedients have not been very successful offshore since they are not adapted to be employed in rough seas.

It is accordingly an object of the present invention to provide a lightweight skimming barrier assembly especially adapted to the concentration, confinement and removal of oil spills from the surface of rough waters.

A further object is to provide a skimming barrier assembly which is so constructed and deployed in the water that it follows the wave motion without allowing the periodic 55 escape of confined oil and without interrupting the collection process for substantial periods of time.

Another object is to provide a skimming barrier assembly which is relatively compact 60 for placement in a container for shipment and yet is sufficiently rugged to withstand the substantial forces encountered in deployment and use.

A particular object is to provide a skim 65 ming sub-assembly suitable for attachment to a floatable barrier sheet.

Accordingly this invention provides a skimming sub-assembly for removing oil floating on water comprising a two part rigid 70 frame adapted, when in use, to be mounted upon an elongated flexible barrier sheet adapted to be supported in generally upright position and partially submerged in the water, said assembly having wall members 75 which are adapted, in conjunction with said sheet when the sub-assembly is attached thereto, to define a tank extending, when in use, from an upper region located at a level above the water to a bottom substantially 80 below the water level, the tank having an inlet opening adapted to be disposed at or near the water level and a conduit extending between the bottom of the tank and an outlet connectible to a suction hose, said tank 85 outlet being adapted, in use, to be disposed at the same level as the inlet at or near the water surface.

The foregoing objects and features together with many advantages of the pres 90 ent invention will become more apparent from the following detailed description of an illustrative embodiment taken in connection with the accompanying drawings, in which:

Figure 1 is a view in perspective of a por 95 tion of a floating skimming barrier assembly shown deployed in a body of water for confining and removing a quantity of floating oil; Figure 2 is a view in rear elevation show 100 Z O 00 xn x" 1 588 989 ing the outside of skimming and flotation sub-assemblies which are parts of the barrier assembly; Figure 3 is a view in front elevation showS ing the inside of a skimming sub-assembly mounted on a barrier sheet; Figure 4 is a view in perspective showing a skimming sub-assembly in condition ready for shipment; Figure 5 is a view partly in cross-section depicting the construction details of the skimming sub-assembly of Figure 3; and Figure 6 is a largely schematic view showing the folding of a barrier assembly to pack it for shipment.

Turning now to the drawings, particularly Figure 1, there is shown a barrier assembly comprising an elongated flexible sheet 10 of rubber or coated fabric, supported at regular intervals by flotation units and extending partly beneath the surface of the water to concentrate the thickness of a quantity of oil by sweeping and to confine the oil in a pool floating on the surface of a body of water.

The flotation units, in those areas of the barrier where no oil is to be collected, are generally of the type already known per se As in the known type, the flotation units which are indicated generally at 14 in Figures 1 and 2, each include an inflatable flotation member 16, a counterweight 18 and a rigid frame 20 The flexible sheet 10 is also stiffened to maintain it in upright position by vertical rigid members 22 In addition, as is also already known, the present barrier also includes a main tension cable 24 to which each frame 20 is connected by lines 26.

The barrier illustrated includes a plurality of skimming sub-assembles according to the invention and each indicated generally at Each sub-assembly 30 includes a rigid outer frame 32 providing a part of the vertical stiffening of the sheet 10 and serving to connect the sheet 10 to an elongated flotation member 34 adapted to float in a horizontal position on the surface of the water and including a counterweight 36 for stability The rigid outer frame 32 is maintained in vertical position in the water by a combination of the flotation member 34 connected directly to the frame, by the buoyancy of a rigid element 39 and by a sufficiently low centre of gravity The distal end of the flotation member 34 is interconnected for stability with the upper and lower portions of the rigid outer frame 32 by guy lines 38 The outer frame 32 is secured to the sheet 10 by means of a plurality of bolts passing through the frame, the sheet 10 and through an inside frame 40, the sheet being clamped between the two frames 32 and 40.

Wall members of an oil gathering tank 42 are welded to the frame 32 and thus form an integral part of it The tank 42 is partially closed at its inner surface and defined by the sheet 10 which is formed with an opening at or slightly above the water line to admit oil from the interior of the barrier, which oil is then trapped in the tank 42 for removal by pumps The tank 42 is formed in part by side 70 walls 44, a rear wall 46 and a bottom wall 48 and also contains a pair of partitions 49 which slope downwardly toward the centre of the tank.

In use, the whole tank 42 lies outside the 75 sheet 10 and includes in its construction a sloping plate 50 which overlies an opening at the top of the tank and closes an opening 52 in the sheet 10 to the passage of oil and water except to the tank A grid 54 is 80 mounted inside the tank 42 in the path of liquids entering through the opening 52 to bar the entry of objects which might clog conduits or damage associated pumping apparatus 85 A conduit 56 leads from the bottom of the tank 42 to a hose connector 58 located above the bottom of the flotation member 34 so as to be at or near the water level, not only to facilitate the connection of a pump 90 hose 60 to the conduit but also in order that the hoses which are designed to float, actually serve to increase the water surface area of the entire assembly and thus aid in stabilizing it to float at a desired water level 95 in waves This provides an important advantage over either submerged or airborne hoses which do not provide stabilizing buoyancy for wave following.

Although the height of the bottom of the 100 opening 52 in the water varies in accordance with the thickness of the oil layer on the water and with the degree of wave activity, the overall design of the built-in buoyancy of the portion of the barrier adjacent the 105 tank 42 is such that the normal or average height of the bottom of the opening is slightly below the water level When the water is thinly covered with oil, the height of the opening is important since it acts in the 110 manner of a dam or weir allowing a thin layer of oil to pass over the bottom of the opening and to cascade into the tank in which the level is kept low by constant pumping so that the oil is removed from the 115 tank in the desired direction.

The manner in which the barrier assembly may be packed for shipment will now be described with particular reference to Figure 6 in which the interior of a shipping con 120 tainer 66 is shown It will first be noted that hose connections 58 to the conduits of the skimming sub-assemblies 30 as shown in Figures 1 and 4 are to the left side of the flotation member 34 as seen from the out 125 side of the barrier assembly However, in order to make more efficient use of the space in the container 66, the skimming sub-assemblies in practice are both right and left hand in the sense that the outlets are 130 1 588 989 either to the right or left of the flotation unit 34 according to the position which they are to occupy in the container In describing the positioning of the various portions of the barrier assembly in the container 66, the flotation units are designated by individual reference numerals 68, 70, 72, 74, 76 and 78 in the order of their occurrence along the barrier sheet 10 Following the flotation unit 78 is a set of six skimming sub-assemblies 80, 82, 84, 86, 88 and 90 progressively along the length of the sheet 10 Following the skimming sub-assembly 90, there are shown flotation units 92, 94, 96 and 98.

The schematic showing of Figure 6 represents a portion of a complete barrier assembly which may include any number of flotation units ahead of the unit 80 and also after the unit 90 In addition, the complete assembly may also include one or more additional sets of skimming sub-assemblies after the group of flotation units 92, 94, 96 and 98 The number of flotation units, skimming sub-assemblies, and the length of the complete barrier assembly used may be varied depending upon several factors such as the size of the oil spill, the prevailing environmental conditions at sea and the equipment available for towing the barrier and for pumping the oil from the skimming sub-assembly tanks.

Starting with the flotation unit 68, there is a length of sheet 10 between the unit 68 and the unit 70 which are spaced apart in the shipping container but oriented in the same direction The next unit 72 is inverted and placed at the end of a first bight formed in another section of sheet 10 between the units 68 and 70.

From the flotation unit 72, a second bight is formed in the sheet 10 and the flotation units 74 and 76 are positioned adjacent the units 68 and 70 respectively and face in the same direction After the unit 76, the sheet 10 is again formed into a bight and the unit 78 is positioned between the two units 74 and 76 and adjacent the unit 72 and facing in the same direction as the unit 72.

From the unit 78, the sheet 10 which is formed into a bight is connected to a skimming sub-assembly 80 which is a left hand unit offset to the right from the position of the flotation unit 74, a distance slightly greater than the diameter of the connector 58 as also seen in Figure 5 From the first skimming sub-assembly 80 the sheet 10 connects the second skimming sub-assembly 82, also a left hand unit, which is oriented in the same direction as the sub-assembly 80 and offset to the right of the flotation unit 76.

The sheet 10 is doubled on itself after the skimming sub-assembly 82 and is connected to the third skimming sub-assembly 84 which is the first right hand sub-assembly, faces in the opposite direction from the sub-assemblies 80 and 82 and is offset to the right from the flotation unit 78 The first three skimming sub-assemblies 80, 82 and 84 are thus offset to the right respectively from the flotation units 74, 76 and 78 From 70 the skimming unit 84, the sheet 10 is again looped over on itself and connected to the skimming sub-assembly 86 and from there to the skimming sub-assembly 88, which is separated by an extended length of the sheet 75 from the skimming sub-assembly 86, both the sub-assemblies 86 and 88 as well as the sub-assembly 84 being right hand units.

The sheet 10 is folded over on itself after the skimming sub-assembly 88 and leads to the 80 skimming sub-assembly 90 a left hand unit placed in line between the sub-assemblies 86 and 88 After the sub-assembly 90, the sheet 10 is again turned over on itself and connected to the first of another succession 85 of flotation units The first flotation unit 92 is followed by a second unit 94 spaced from the first and after a bight in the sheet by a third unit 96 in a line between the units 92 and 94 Following the unit 94, the sheet 10 90 is again turned over on itself and connected to another flotation unit 98 and the succession of flotation units and/or skimming sub-assemblies continues as above indicated 95

Claims

WHAT I CLAIM IS:

1 A skimming sub-assembly for removing oil floating on water comprising a two part rigid frame adapted, when in use, to be mounted upon an elongated flexible barrier 100 sheet adapted to be supported in generally upright position and partially submerged in the water, said assembly having wall members which are adapted, in conjunction with said sheet when the sub-assembly is 105 attached thereto, to define a tank extending, when in use, from an upper region located at a level above the water to a bottom substantially below the water level, the tank having an inlet opening adapted to be disposed at 110 or near the water level and a conduit extending between the bottom of the tank and an outlet connectible to a suction hose, said tank outlet being adapted, in use, to be disposed at the same level as the inlet at or 115 near the water surface.

2 A skimming sub-assembly according to claim 1 further characterised in that the parts of the frame are adapted to be mounted respectively on inner and outer 120 surfaces of the sheet, whereupon the inlet opening is located at the inner surface of the sheet and the outlet conduit is located outside the outer surface of the barrier sheet.

3 A skimming sub-assembly according 125 to claim 2 further comprising an elongated inflatable float connected to the frame and, in use, capable of extending horizontally on the surface of the water from the outer surface of the sheet and further characterised in 130 1 588 989 that the conduit includes a connector for a pump hose, adapted in use to be located at a level slightly above the bottom of the float.

4 A skimming sub-assembly according to claim 2 further characterised in that the wall members adapted to define parts of the tank are an integral part of the outer frame and are formed with an open side which is only adapted to be partially closed by the sheet, leaving the inlet to the tank above the waver level when the sub-assembly, in use, is attached to the barrier sheet.

A floatable skimming barrier assembly comprising an elongated flexible sheet, a plurality of flotation units located at spaced-apart intervals along the length of the sheet, each unit including an inflatable float connected to the sheet for maintaining it in generally upright position and partially submerged in the water, and in combination 20 with said sheet and said flotation units connected thereto, at least one skimming subassembly, as defined in any one of claims 1 to 4, also connected to the sheet.

6 A floatable barrier in combination 25 with at least one skimming sub-assembly, all according to claim 5 and substantially as described with reference to the accompanying drawings.

7 A skimming sub-assembly according 30 to any one of claims 1 to 4 and substantially as described with reference to the accompanying drawings.

HYDE, HEIDE & O'DONNELL 2 Serjeant's Inn EC 4 Y ILL Agents for Applicant Printed for Her Majesty's Stationery Office by The Tweeddale Press Ltd Berwick-upon-Tweed, 1981 Published at the Patent Office, 25 Southampton Buildings, London, WC 2 A I AY, from which copies may be obtained.